Well, we all found out the answer in 2005. In the Atlantic and East Pacific,
when they have run through the name list they then use the Greek alphabet :
Alpha, Beta, Gamma, Delta, Epsilon,... etc. . At present there are no
plans to retire letters of the Greek alphabet from the list, but if a
very bad hurricane occurs with a Greek letter name, this may have to be
revised.

In the Central and West Pacific they have a perpetual lists of names, so
when one list is through they simply start on the next.

Since the name list has been started in the Atlantic in 1950
the furthest they have gone down the list has been Tropical Storm
Zeta in 2005.